What is staging and why is it important?
The STAGE of lung cancer describes if and where the cancer has spread. The cancer has to be staged before treatment options can be known. Imaging tests, biopsies and other tests all help to tell the stage.
Lung cancer is staged using the TNM staging system. TNM is one of the most commonly used cancer staging systems in the world.
TNM looks at the size of the tumor (T); if and how much the cancer has spread to the lymph nodes (N); & if and how far the cancer has spread beyond the lymph nodes (M for metastasis).
Non-Small Cell Lung Cancer
Non-small cell lung cancer (NSCLC): To learn more each stage and treatments for NSCLC based on stage, click the following links for our one pagers on this topic. stage I, stage II, stage III and stage IV.
Watch the educational video below to learn more about non-small cell lung cancer and its staging.
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Small Cell Lung Cancer
Small cell is also staged using TNM but the older way of staging may still be in use:
- Limited-stage indicates that the cancer has not spread beyond one lung and the lymph nodes near that lung.
- Extensive-stage indicates that the cancer is in both lungs or has spread to other areas of the body.
Watch the educational video below to learn more about small cell lung cancer staging and explore additional small cell lung cancer educational resources.
How Does The TNM Staging System Work?
T is for Tumor
How big is the tumor? Where is it located? Has it spread to nearby tissue?
| TX | Tumors are too small for testing, or their exact location cannot be found with tests. |
| T0 | No primary or original tumor has been found. |
| Tis | There are abnormal or cancer cells in the top layer of cells in the breathing tubes that have not spread to other lung tissue. |
| T1 | Tumors are only in the lungs and are smaller than 3cm (the size of one grape). |
| T1mi | Tumors grow only along the surface of lung tissue and are less than 0.5cm deep into the tissue of the lung. |
| T1a | Tumors are smaller than 1cm (the size of a pea) and has not reached the tissues that surround lungs, or the main branches of the airways. |
| T1b | Tumors are between 1cm (size of a pea) and 2cm (size of a peanut) and have not reached the tissues that surround the lungs or the main branches of the airways. |
| T1c | Tumors are between 2cm (size of a peanut) and 3cm (size of a grape) and has not reached the tissues that surround the lungs, or the main branches of the airways. |
| T2 | Tumors are between 3cm (size of a grape) and 5cm (size of a lime) and/or has grown into the main bronchus (the two airway tubes that split off of the windpipe) and/or has grown into the lung’s inner lining (visceral pleura) and/or has caused lung collapse (atelectasis) or swelling (pneumonitis). |
| T2a | Tumors are between 3cm (size of a grape) and 4cm (size of a walnut) and has grown into the main airways and/or the tissue around the lungs. |
| T2b | Tumors are between 4cm (size of a walnut) and 5cm (size of a lime) and has grown into the main airways and/or the tissue around the lungs. |
| T3 | Tumors are between 5cm (size of a lime) and 7cm (size of a peach) and/or has grown into the chest wall, or nearby sites and/or there are other tumors are in the same lobe of the lung. |
| T4 | Tumors are larger than 7cm (size of a peach) and/or has grown into the center of the chest, to the diaphragm, heart or its major blood vessel, windpipe, area where the windpipe divides, esophagus (food tube), or spine (backbone) and/or there are other tumors are in the same lobe of the lung. |
N is for Lymph Node
This describes whether cancer has spread to the lymph nodes in and around the lungs.
| N0 | There is no cancer in lymph nodes near the cancer. |
| N1 | Cancer has spread to the lymph nodes near the area where the windpipe divides and/or to nodes in the center of the chest and in the lung with the primary tumor. |
| N2 | Cancer has spread to other nodes in the center of the chest near the lung with the original tumor. |
| N3 | Cancer has spread to nodes in the center of the chest (mediastinal or hilar) near the lung without the primary tumor OR to any nodes in the neck or near the collarbone (supraclavicular or scalene nodes). |
M is for Metastasis
The describes whether the cancer has spread to areas outside the lymph nodes.
| M0 | Cancer has not spread to far away sites. |
| M1 | Cancer has spread to far away sites. |
| M1a | Cancer has spread from one lung into the other OR into the lining and has formed nodule(s) OR into the lining of the heart and has formed nodule(s) OR into the fluid around the lungs or the heart. |
| M1b | Cancer has spread to one site outside the chest area. |
| M1c | Cancer has spread to more than one site outside the chest area. |
Stages
After the Tumor (T), Lymph Nodes (N) and Metastasis (M) are known, the cancer then is staged:
| Overall Stage | T | N | M |
| Stage 0 | Tis (in situ) | N0 | M0 |
| Stage 1A1 | T1mi, a | N0 | M0 |
| Stage 1A2 | T1b | N0 | M0 |
| Stage 1A3 | T1c | N0 | M0 |
| Stage 1B | T2a | N0 | M0 |
| Stage 2A | T2b | N0 | M0 |
| Stage 2B | T1a T1b T1c T2a T2b T3 |
N1 N1 N1 N1 N1 N0 |
M0 M0 M0 M0 M0 M0 |
| Stage 3A | T1a T1b T1c T2a T2b T3 T4 T4 |
N2 N2 N2 N2 N2 N1 N0 N1 |
M0 M0 M0 M0 M0 M0 M0 M0 |
| Stage 3B | T1a T1b T1c T2a T2b T3 T4 |
N3 N3 N3 N3 N3 N2 N2 |
M0 M0 M0 M0 M0 M0 M0 |
| Stage 3C | T3 T4 |
N3 N3 |
M0 M0 |
| Stage 4A | Any T Any T |
Any N Any N |
M1a M1b |
| Stage 4B | Any T | Any N | M1c |
Source:
American Joint Committee on Cancer. Lung. In: AJCC Cancer Staging Manual. 8th ed. New York, NY: Springer; 2017: 431-456.